composable-commerce

A composable commerce architecture based on MACH principles decouples commerce capabilities like catalog, search, and checkout into independent services. It implements a Backend-for-Frontend for API aggregation and uses event-driven sagas to coordinate cross-service workflows reliably.

A BFF, or Backend-for-Frontend, aggregates multiple backend services into a single frontend-friendly API in headless commerce. It uses GraphQL schema stitching to combine distributed data from independent services into unified responses for multi-storefront delivery.

Event-driven sagas handle distributed transactions in microservices by coordinating asynchronous events across independent services. They implement compensating transactions to roll back failed operations, ensuring data consistency without requiring distributed locks across service boundaries.

Replatforming a monolith to a headless stack preserves multi-storefront delivery by splitting capabilities into independent services. Teams can adopt best-of-breed vendors for commerce, search, and CMS while maintaining uptime through circuit breakers and API versioning.

Implementing observability for event-driven commerce requires distributed tracing with OpenTelemetry across all independent services. This approach tracks asynchronous events through cross-service workflows, providing operational visibility into saga execution and circuit breaker states.

You should not use a composable commerce approach if your platform lacks the engineering capacity to manage distributed systems. The architecture introduces complexity through service boundary design, event-driven coordination, and distributed tracing, which may outweigh benefits for smaller monolithic applications.